Use single thread for executing events insted of cached thread pool

Author: kklisura

cdt-java-client/src/main/java/com/github/kklisura/cdt/services/executors/DefaultEventExecutorService.java

@@ -29,7 +29,7 @@
  * @author Kenan Klisura
  */
 public class DefaultEventExecutorService implements EventExecutorService {
-  private ExecutorService executorService = Executors.newCachedThreadPool();
+  private ExecutorService executorService = Executors.newSingleThreadExecutor();
 
   @Override
   public void execute(Runnable runnable) {